Remote-control system



Oct. 22, 1929. w. R. G. BAKE]? REMOTE CONTROL SYSTEM Filed Dec. 29, 1925 Inventor Walter RGBaken bg Puma ca;-

' UNITED STA ES PATENT. orrlca v n. c. or sonxnc'ramr, new roux, -.assrcnon r enmmannmo:

- rmc comm, a couroiwrron-or rmw roux sysrmr Application flied December a, 1926. semi m. 78,217.

My invention -relates to remote control. systems and more particularly to means for controlling a circuit at a remote point by means of carrier current supplied to a systom ofdistribution.

It has heretofore been proposed to employ carrier current systems to control remote circuits. Such systems usuall employ an electric discharge device in t e nature of a glow tube as a detector of the carrier frequency current. In the present device, instead of a glow tube, a three-element electric discharge device is employed as a detector of the high frequency current. The use of a dischar e device of this character presentsthe di culty that the filament may burn out and thereby render the system inqperative, and it is one of the objects o my invention to provide means wherebythis difiiculty may be oaen'come.

The novel features which I believe to be characteristieof my invention are set forth with particularity in the appended claim. My. invention itself, however,ibothf as to its organization and method of operation ,will best be understood by reference to the following specification taken in connection with the accompanying drawing in which the single figure shows diagrammatically a circuit organization whereby my invention mag be carried into efiect. p

- eferring to the drawing, I have indicated at 1, the mains of a system of distribution. Associated with the system is a receiver which includes a transformer 2, an electric discharge device 3, and a-relay 4. Transformer 2 consists of aprimary winding 5 connected to the distribution system through coupling condensers 6, which also serve to exclude current of power frequency from the receiver. The secondary windin 7 of the transformer is connected to the gri S and cathode 9 of the three-element discharge' device 3. A condenser 10 is connected across the secondary winding 7 and serves to tune the receiver to the frequency of the carrier current employed. A source of energy 11, which in the present instance is a battery, is connected to 'the grid 8, and supplies a negative bias thereto, so that nor- .mally no current flows inftlieoutput circuit of the discharge'device. The output circuit of the discharge. device includes an anode 12, a source of energy 13 anda relay/l, the

latter being adapted-to control the remote circuit14. Heating current for cathode 9 is supplied from. the secondary winding of a transformer 15, which may be connected by a double pole switch 16, to an alternatingz current source indicated at 17.

elay 4 includes a switch arm 18 which opens and closes the remote circuit-14, the arm being actuated to the position indicated on the drawing by means of- 'a spring 19. The winding of relay 4 is adapted under certain conditions to be connected in circuit with the alternating current source 17 through a switch 20, and a glow tube or discharge device 21. The glow tube 21 comprises a receptacle filled at a certain pressure with an inert gas, such as neon, and having two dissimilar electrodes therein as indicated at 22 and 23. -Owing to the dissimilar-character of the electrodes, current will flow through the tube 21 in one direction only. An electromagnet 24, the winding of which is included ncircuit with the cathode :9, controlsvthe operation of switch arm 20.

Normally, when switch 16' is in closed posi tion, the filamentary cathode 9 willbe supplied with heating current from transformer.. 15, electromagnet 24, which is in circuit with cathode 9, will be energized, and switch arm 20 will be moved against the dead contact in-" dicated at 25, thus opening and maintaining open the circuit from the alternating current I source 17 to the winding of relayf l. 1 Under such circumstances, when carrier current ha'ving a certain frequency for which the circuit of the device 3 is tuned, is supplied from a transmitter, not shown, to the distribution system 1, the carrier frequency current will be detected by the discharge device 3, grid 8 will be rendered alternatel positive and negative, and current will ow in the output circuit of the discharge device, ing the winding 0 relay 4 and opening re mote circuit 14.

If the current flowing through the filamenthereby energiztary cathode 9 should for any reason become interrupted, electromagnet 24 would become deener 'zed, and the switch arm would be immediately released and actuated, either by its own weight or by means of a spring, not shown, to the position indicated on the rawing. In the latter position a circuit would be closed from the alternating current source 16, through switch arm 20 and glow tube 21 to the relay 4, thus maintaining the energization of relay 4, independently of the discharge device 3.

Instead of the source 17 current may be supplied if desired from the mains 1. Va-

- rious modifications of my invention will readily suggest themselves to persons skilled in the art without departing from the scope of my invention as set forth in the appended claim.

What I claim as new and desire to secure by Letters Patent of the United States, is:

In combination, an electron dischar e de- Vice having a cathode circuit,an ano e circuit, and a grid circuit, a relay connected in said anode circuit, means for supplying con trol current to said grid circuit thereby to control the operation of said relay, a source of potential for energizing said cathode circuit, a relay connected in said cathode circuit and connections from said source of potential to said first-mentioned relay, said connections including contacts on said second-mentioned relay whereby upon failure of current-in said cathode circuit said first-mentioned relay becomes energized from said cathode source of potential.

In witness whereof, I have hereunto set my handthis 28th da of December, 1925.

W- TER R. G. BAKER. 

